1. Introduction
This series of posts assumes that you have already memorized the names of the 47 project management processes, and you are ready to go on to the task of memorizing the tools & techniques. This post covers chapter 6 of the 5th Edition PMBOK® Guide, the Time Knowledge Area.
2. Time Management Area Processes
Here’s a description of the seven processes that are included in the Time Knowledge Area, together with a listing of the Tools & Techniques used in those processes.
Process Name | Process Description | Tools & Techniques |
6.1 Plan Schedule Management | Establishes the policies, procedures, and documentation for all project schedule-related processes. | 1. Expert judgment
2. Analytical techniques 3. Meetings |
6.2 Define Activities | Identities and documents activities to be performed to produce the project deliverables. | 1. Decomposition
2. Rolling wave planning 3. Expert judgment |
6.3 Sequence Activities | Identifies and documents relationships among the project activities. | 1. Precedence diagramming method (PDM)
2. Dependency determination 3. Leads & lags |
6.4 Estimate Activity Resources | Estimates type and quantities of resources (material, human resources, equipment, or supplies) required to perform each activity. | 1. Expert judgment
2. Alternative analysis 3. Published estimating data 4. Bottom-up estimating 5. Project management software |
6.5 Estimate Activity Durations | Estimates the number of work periods needed to complete individual activities with specified resources. | 1. Expert judgment
2. Analogous estimating 3. Parametric estimating 4. Three-point estimating 5. Group decision-making techniques 6. Reserve analysis |
6.6 Develop Schedule | Analyzes activity sequences, durations, resource requirements, and schedule constraints to create the project schedule model. | 1. Schedule network analysis
2. Critical path method 3. Critical chain method 4. Resource optimization techniques 5. Modeling techniques 6. Leads & lags 7. Schedule compression 8. Scheduling tool |
6.7 Control Schedule | Monitors status of project activities to update project progress and manage changes to schedule baseline in order to achieve the plan. | 1. Performance reviews
2. Project management software 3. Resource optimization techniques 4. Modeling techniques 5. Leads & lags 6. Schedule compression 7. Scheduling tool |
3. Time Management Area Tools & Techniques
Since the time management area has the most processes of all the knowledge areas, 7 in total, and some of these have up 7 or 8 tools & techniques each, this is probably one the more complicated areas to memorize tools & techniques. Rather than going through each one individually, I will pick up some individual tools & techniques, plus some tools & techniques which are best memorized in groups because they are thematically related and often used as part of the same process.
a. Expert judgment (6.1 Plan Schedule Management, 6.2 Define Activities, 6.4 Estimate Activity Resources, 6.5 Estimate Activity Durations)
This tool is used on a lot of planning processes in each knowledge area not just for this particular knowledge area. Remember that for project management, an expert is either someone who is considered a subject matter expert or SME (a consultant) OR someone who is considered an expert on a specific part of the project (a team member). The subject matter expert has generalized knowledge about a subject, and the team member expert has specialized knowledge about a specific aspect of the project. You use expert judgment to consult:
- those who worked on previous projects to see how the schedule was managed on those projects (6.1 Plan Schedule Management), what resources were required on those projects (6.4 Estimate Activity Resources), and how long activities took on those projects (6.5 Estimate Activity Durations)
- those with specialized knowledge of the project scope statement and the work breakdown structure (WBS), in order to take each work package and define the activities required to complete them
b. Analytical techniques, Meetings (6.1 Plan Schedule Management)
Analytical techniques are usually used when there is some sort of strategic decision to be considered, and in the planning phase, you may have to decide which estimating technique to use, whether to use a schedule compression technique such as fast tracking or crashing, and how project risks may affect the schedule.
Because so many stakeholders are affected by the project schedule, meetings are needed to gather input from as many of those stakeholders as possible, and to obtain buy-in from those stakeholders at the earliest stage of planning in order to prevent as many changes from occurring farther down the line.
c. Decomposition, Rolling Wave Planning (6.2 Define Activities)
It should be pretty clear that decomposition is a tool of 6.2 Define Activities, because it is going from the WBS (the work breakdown structure), which has work packages as the smallest unit of scope to be completed, and translating that into activities which are required to create those work packages. It is the first step in translating units of scope into units of time. Another way to think of it is that you are taking work packages which are nouns, and translating them into activities, which are verbs.
Rolling Wave Planning is a technique of progressive elaboration, where the initial activities are planned in greater detail, and the activities which come later in the future are planned in less detail. A visual analogy is that of a train coming down the tracks, when not all of the tracks have been laid down yet for the entire route. You need to place priority in having the tracks directly in front of the train already in place, while others who are scouting ahead are looking at the terrain and placing the tracks in the areas that the train will get to later on.
d. Precedence Diagramming Method (PDM), Dependency Determination (6.3 Sequence Activities)
Dependency Determination is used to figure out whether activities have mandatory vs. discretionary dependency, and internal vs. external dependency. Mandatory dependencies are a) legal or contractual, or b) inherent in the nature of the work (i.e., concrete must be allowed to harden before load is placed on it). Discretionary dependencies are based on best practices, but can be altered if required for fast tracking or crashing, whereas mandatory dependencies have no such flexibility.
External dependencies are outside of the project team’s control and internal dependencies are within the project team’s control. Thus fast tracking or crashing must choose those dependencies which are internal, and not external, to work on.
Precedence Diagramming Method constructs a schedule model by representing each activity by a node (graphically represented by a box) that is connected in one of four possible ways to its successor activity: finish-to-start (most common), start-to-start, finish-to-finish, and start-to-finish (least common). For example, with finish-to-start, the successor activity cannot start until a predecessor activity has finished.
e. Alternative Analysis, Published Estimating Data, Bottom-Up Estimating (6.4 Estimate Activity Resources)
The keyword that links all of these tools & techniques together is the word resources. Logically speaking, you cannot figure out how long an activity is going to take until you first know the quantity of resources available to work on that activity. That is why 6.4 Estimate Activity Resources comes before 6.5 Estimate Activity Durations.
Alternative Analysis gives the different alternative resources that can be used to achieve the same activity.
Published Estimating Data gives data on the unit costs of various resources that can be used on the project.
Bottom-Up Estimating takes the individual estimate for the quantity of resources that is used to do each activity required to produce a work package, and these individual estimates are summed up to get the total amount of resources required to produce that work package.
f. Analogous Estimating, Parametric Estimating, Three-Point Estimating, Group Decision-Making Techniques, Reserve Analysis (6.5 Estimate Activity Durations)
The keyword that links all of these tools & techniques together is the word durations.
Analogous Estimating and Parametric Estimating are BOTH based on historical data from previous projects, but analogous estimating is based on the production of the whole project whereas parametric estimating is based on a unit cost of doing the project. For example, let’s say you want to estimate the cost of building a new house in a subdivision. There are two ways of going about it: one is to get an estimate of how much it cost to build an entire house in that subdivision in the past. If the model of your new house is similar to that of the previously existing one, then you can create an analogous estimate. However, you can also, figure out how much it cost to build that previous existing house per square foot of space. Then you can use that unit cost to estimate how much it will cost to build your new house.
Three-Point Estimating is where the world of risk management starts entering into time management. Each estimate of an activity should have three components, the most likely estimate t(M), the pessimistic estimate (tP), and the optimistic estimate (tO). The pessimistic and optimistic estimate will be based on an analysis of risk assumptions that are either opportunities (+) or threats (-) to the schedule. How these three estimates are combined into a final estimate (tE) depends on what distribution you are using:
- Triangular: tE = (tO + tM + tP/3)
- Beta: tE = (tO + 4tM + tP)/6
Group Decision-Making Techniques are used to brainstorm with all of your team members as a group in order to improve estimate accuracy.
Reserve Analysis is another way in which risk management enters into time management. Based on analysis of possible risks that may affect the schedule, it use Contingency Reserves in the form of time reserves or buffers to account for schedule uncertainty. If risks that are anticipated at certain points in the project do not materialize, then those buffers can be absorbed and the schedule possibly shortened as a result.
g. Schedule Network Analysis, Critical Path Method, Critical Chain Method, Resource Optimization Techniques, Modeling Techniques, Leads and Lags (6.6 Develop Schedule, 6.7 Control Schedule)
Once you know what the activities are (6.2), you have the sequence in which you are to do them (6.3), you know the resources you have to do them (6.4), and you know how long it will take to do them (6.5), you can then fit all of this together into the schedule model, which is the key phrase that links all of the above tools & techniques together.
Schedule Network Analysis is an all encompassing term for techniques used to build the schedule model, and this includes the next three techniques of the Critical Path Method, the Critical Chain Method, and Resource Optimization Techniques.
The Critical Path Method determines which activities are on the critical path of the project, which means that any delay in these activities will delay the entire project. Those activities that are not on the critical path are said to be on a non-critical path, and have a certain amount of float. An activity that has three days float will not cause any delay to the critical path unless it is delayed for more than three days.
The Critical Chain Method adds buffers to prevent any delays along the critical path or non-critical path which would impact the finishing date of the project.
Resource Optimization Techniques takes into account the fact that, although it may take a certain amount of work periods to complete an activity if the theoretical maximum of 100% of the resources are available, since resources must be shared among projects, there may be some activities that can only use a smaller portion of those resources, which will mean that the activity will take longer.
Finally, Leads & Lags are those activities which must start earlier (leads) or later than (lags) their predecessor activities finish. Although these are analyzed in 6.3 Sequence Activities, they must be inserted in the schedule model (6.6) to make sure that activities flow smoothly from one to the next.
h. Schedule Compression (6.6 Develop Schedule, 6.7 Control Schedule)
Once the schedule model is created using the techniques mentioned in paragraph g), what if it says the project will take longer than the basic time constraint you have to work with? Here is where you need to investigate the techniques of fast-tracking (doing activities in parallel which were earlier planned to be done in sequence) and crashing (adding more resources to get the job done in less time). Crashing is, in effect, the opposite of resource optimization techniques like resource leveling, described in the previous paragraph. When your resources are limited, you may have to take more time than you had planned (that is what resource optimization is about). Conversely, if your time is limited, however, you may have to spend more resources than you had planned in order to get that activity done in that limited time (that is what crashing an activity is about). Fast-tracking reduces the time, but the offset is that increases the risk that the work done may be of lower quality and may have to be redone. So schedule compression techniques generally require a trade-off of some kind.
j. Project Management Software, Scheduling Tool (6.4 Estimate Activity Resources, 6.6 Develop Schedule, 6.7 Control Schedule)
These are tools that are used to take the resources and apply them to activities (6.4), and then to build the schedule model (6.6). Microsoft Project and Primavera are examples of such tools.
k. Performance Reviews (6.7 Control Schedule)
This does not mean performance reviews of team members, but reviews of how the project is performing in actuality as opposed to how it is supposed to be going according to plan. If is not going according to plan, this will necessitate changes to the schedule. This is why some of the techniques in the last paragraphs can be used not just in developing the schedule (6.6), but making changes to that schedule as well (6.7).
This is quite a long list of tools & techniques, but if you analyze what the process does, the tool & technique used to accomplish that process should make sense.
The next post covers the next chapter of the PMBOK® Guide, chapter 7 which covers the knowledge area of cost management.
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